Move metamigo assets to metamigo-add

apps/link/metamigo-add/_lib/dataprovider.ts

@@ -0,0 +1,12 @@
+import pgDataProvider from "ra-postgraphile";
+import schema from "./graphql-schema.json";
+
+export const metamigoDataProvider = async (client: any) => {
+  const graphqlDataProvider: any = await pgDataProvider(
+    client,
+    // @ts-expect-error: Missing property
+    {},
+    { introspection: { schema: schema.data.__schema } }
+  );
+  return graphqlDataProvider;
+};